Line concentration system

ABSTRACT

A line concentration system containing: a plurality of data input/output circuits; a plurality of first-side transmission lines to each of which one of a plurality of data input/output circuits can be connected; a second-side transmission line, and a data input/output timing controller. The second-side transmission line is connected with the above plurality of first-side transmission lines, and is capable of transmitting a predetermined number of channels of data. Each of the above data input/output circuits inputs/outputs data at a controlled timing from/onto the first-side transmission line to which its own data input/output circuits is connected. The data input/output timing controller controls the timings of the above inputs/outputs by the above plurality of data input/output circuits so that data input/output operations in two of the data input/output circuits are not simultaneously carried out. In addition, the line concentration system further contains a connection switching circuits, which is provided for connecting a controlled number of corresponding first-side transmission lines with the second-side transmission line; and the controlled number can be selected among a plurality of predetermined numbers.

BACKGROUND OF THE INVENTION

(1) Technical

The present invention relates to a line concentration system, which is in particularly useful in a small size exchange system, e.g., a private branch exchange system.

(2) Description of the Related Art

In a rather large size exchange system, e.g., in an exchange station in a public telephone network, line concentrators are provided between line circuits and speech path exchange circuits for handling a greater number of channels in a subscriber side in an exchange circuit side. Concentration rates for concentrators are respectively selected according to traffic intensities in the subscriber side capacities in the exchange circuit side. Generally, less traffic in the subscriber side requires a greater concentration rate in a concentrator to effectively utilize the total capacity of the exchange system.

However, in conventional concentrators, a concentration rate in a concentrator cannot be easily changed, i.e., the concentration rate is fixed. Further, in a rather small size exchange system, e.g., a private branch exchange system, no concentrator is provided, i.e., the concentration rate is one.

Namely, in the conventional exchange system, to change a concentration rate, a plurality of concentrators for respective concentration rates must be provided. Therefore, ineffective spaces for installing a plurality of concentrators are necessary in the conventional exchange system, and a troublesome operation is necessary to disconnect a group of subscriber channels from one concentrator and connect the group to another concentrator to change the concentration rate.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a line concentration system, wherein a concentration rate is easily changed, and ineffective spaces for installing a plurality of concentrators for a group of subscriber channels are unnecessary.

According to the first aspect of the present invention, there is provided a line concentration system comprising: a plurality of data input means; a plurality of first-side transmission lines to each of which one or more data input means can be connected; a second-side transmission line connected with the above plurality of first-side transmission lines, and being capable of transmitting a predetermined number of channels of data; and a data input timing control means. Each of the above data input means inputs data at a controlled timing from the first-side transmission line to which its own data input means is connected. The above data input timing control means controls the timings of the above inputs by the above plurality of data input means so that data input operations in two of the data input means are not simultaneously carried out.

According to the second aspect of the present invention, there is provided a line concentration system comprising: a plurality of data output means; a plurality of first-side transmission lines to each of which one or more data output means can be connected; a second-side transmission line connected with the above plurality of first-side transmission lines, and being capable of transmitting a predetermined number of channels of data; and a data output timing control means. Each of the above data output means outputs data at a controlled timing onto the first-side transmission line to which its own data output means is connected. The data output timing control means controls the timings of the above outputs by the above plurality of data output means so that data output operations in two of the data output means are not simultaneously carried out.

According to the third aspect of the present invention, there is provided a line concentration system comprising: a plurality of data input means; a plurality of first-side transmission lines to each of which one of the above plurality of data input means can be connected; a plurality of second-side transmission lines; a connection switching means, provided between the above plurality of first-side transmission lines and the above plurality of second-side transmission lines, for connecting a controlled number of corresponding first-side transmission lines with a corresponding one of the plurality of second-side transmission lines; and a data input timing control means. Each of the above plurality of second-side transmission lines being capable of transmitting a predetermined number of channels of data. Each of the above data input means inputs data at a controlled timing from the first-side transmission line to which its own data input means is connected. The above data input timing control means controls the timings of the above inputs by the above plurality of data input means so that data input operations in two of the data input means from the corresponding first-side transmission lines which are connected to one of the second-side transmission lines, are not simultaneously carried out. In the above connection switching means, the above controlled number can be selected from among a plurality of predetermined numbers.

According to the fourth aspect of the present invention, there is provided a line concentration system comprising: a plurality of data output means; a plurality of first-side transmission lines to each of which one of the above plurality of data output means can be connected; a plurality of second-side transmission lines; a connection switching means, provided between the above plurality of first-side transmission lines and the plurality of second-side transmission lines, for connecting a controlled number of first-side transmission lines with a corresponding one of the plurality of second-side transmission lines; and a data output timing control means. Each of the above plurality of second-side transmission lines being capable of transmitting a predetermined number of channels of data. Each of the above data output means outputs data at a controlled timing onto the first-side transmission line to which its own data output means is connected. The above data output timing control means controls the timings of the above outputs by the above plurality of data output means so that data output operations from two of the above data output means onto the corresponding first-side transmission lines which are connected to one of the second-side transmission lines, are not simultaneously carried out. In the above connection switching means, the above controlled number can be selected from among a plurality of predetermined numbers.

BRIEF DESCRIPTION OF DRAWINGS

In the drawings:

FIGS. 1 and 2 each show a basic principle of the present invention;

FIGS. 3 and 4 snow an outline of the construction of a small size exchange system, such as a private branch exchange system;

FIG. 5 shows, the construction of the subscribers package in FIG. 4;

FIG. 6 shows the assignment of time slots on each data highway 3₀, 3₁, 3₂, ... 3₇, 4₀, 4₁, 4₂, ... 4₇ in the construction of FIG. 4;

FIG. 7 shows the connections of the plurality of subscribers packages 1₀, 1₁, 1₂, ... 1₁₅ with the data highways 3₀, 3₁, 3₂, ... 3₇, or data highways 4₀, 4₁, 4₂, ... 4₇ in the non-concentrated connection mode in the construction of FIG. 4;

FIG. 8 shows the connections of the plurality of subscribers packages 1₀, 1₁, 1₂, ... 1₁₅ with the data highways 3₀, 3₁, 3₂, ... 3₇, or data highways 4₀, 4₁, 4₂, ... 4₇ in the concentrated connection mode with a concentration rate of two in the construction of FIG. 4;

FIG. 9 shows the arrangement of the connections of the plurality of subscribers packages 1₀, 1₁, 1₂, ... 1₁₅ with the data highways 3₀, 3₁, 3₂, ... 3₇, 4₀, 4₁, 4₀, ... 4₇ in the connection unit 26 in the construction of FIG. 4;

FIGS. 10 and 11 show the construction of the first embodiment of the present invention for allowing the change of the concentration rate; and

FIGS. 12 and 13 show the construction of the second embodiment of the present invention for allowing the change of the concentration rate.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Before describing the preferred embodiment of the present invention, first, a basic construction which is used in the present invention is explained below.

FIGS. 1 and 2 each show a basic construction which is used the present invention. FIG. 1 corresponds to the aforementioned first aspect of the present invention, and FIG. 2 corresponds to the aforementioned second aspect of the present invention.

In FIG. 1, reference numeral 49₀, 49₁, 49₂, ... 49_(m) denotes a plurality of first-side transmission lines, 69 denotes a second-side transmission line, 17₀, 17₁, 17₂, ... 17_(p) denotes a plurality of data input circuits, and 16 denotes a data input timing control circuit.

One (or more) of data input circuits 17₀, 17₁, 17₂, ... 17_(p) is connected to each of the plurality of first-side transmission lines 49₀, 49₁, 49₂, ... 49_(m).

The plurality of first-side transmission lines 49₀, 49₁, 49₂, ... 49_(m) are connected with the second-side transmission line 69, and the second-side transmission line 69 can transmit a predetermined number of channels of data.

Each of the data input circuits 17₀, 17₁, 17₂, ... 17_(p) inputs data at a controlled timing from the first-side transmission line to which its own data input circuit is connected.

The data input timing control circuit 16 controls the timings of the inputs by the plurality of data input circuits 17₀, 17₁, 17₂, ... 17_(p) so that data input operations in two of the data input circuit are not simultaneously carried out.

In the construction of FIG. 1, multiplexed data (including a plurality of channels of data), which is transmitted on the second-side transmission line 69, is then transmitted on each of the first-side transmission lines 49₀, 49₁, 49₂, ... 49_(m) in parallel. Under the control of the data input timing control circuit 16, each of the data input circuits 17₀, 17₁, 17₂, ... 17_(p) can input data on one or more channels which are determined by the control of the data input timing control circuit 16, from the multiplexed data on a first-side transmission line to which the data input circuit is connected, where data on each channel is not doubly input into two or more data input circuits, although the plurality of data input circuits 17₀, 17₁, 17₂, ... 17_(p) are respectively connected to different transmission lines 49₀, 49₁, 49₂, ... 49_(m) in the first side.

Namely, data in the plurality of channels of a multiplexed data on the second-side transmission line 69 can be respectively delivered to a plurality of data input circuits 17₀, 17₁, 17₂, ... 17_(p) through a plurality of first-side transmission lines 49₀, 49₁, 49₂, ... 49_(m), under the control of the data input timing control circuit 18.

In FIG. 2, reference numerals 39₀, 39₁, 39₂, ... 39_(m) denote a plurality of first-side transmission lines, 59 denote a second-side transmission line, 19₀, 19₁, 19₂, ... 19_(p) denotes a plurality of data output circuits, and 18 denotes a data output timing control circuit.

One (or more) of data output circuits 19₀, 19₁, 19₂, ... 19_(p) is connected to each of the plurality of first-side transmission lines 39₀, 39₁, 39₂, ... 39_(m).

The plurality of first-side transmission lines 39₀, 39₁, 39₂, ... 39_(m) are connected with the second-side transmission line 59, and the second-side transmission line 59 can transmit a predetermined number of channels of data.

Each of the data output circuits 19₀, 19₁, 19₂, ... 19_(p) outputs data at a controlled timing onto the first-side transmission line to which its own data output circuit is connected.

The data output timing control circuit 18 controls the timings of the outputs by the plurality of data output circuits 19₀, 19₁, 19₂, ... 19_(p) so that data output operations in two of the data output circuit are not simultaneously carried out.

In the construction of FIG. 2, data which is transmitted on the plurality of first-side transmission lines 39₀, 39₁, 39₂, ... 39_(m), are logically summed, and the logically summed data is then transmitted on the second-side transmission line 59. Here, under the above control of the data output timing control circuit 18, the data output circuits 19₀, 19₁, 19₂, ... 19_(p) which are connected to respective first-side transmission lines 39₀, 39₁, 39₂, ... 39_(m), each output their output data at a different timing from each other onto the first-side transmission line to which its own data output circuit is connected. Therefore, no data superposes on the second-side transmission line 59. Namely, data which are output from a plurality of data output circuits 19₀, 19₁, 19₂, ... 19_(p) which are connected to respective first-side transmission lines 39₀, 39₁, 39₂, ... 39_(m), can be concentrated to a multiplexed data on the second-side transmission line 59 under the control of the output timing control circuit 18.

The above constructions of FIGS. 1 and 2, are applicable to a construction of a line concentrator, i.e., a line concentrator which can receive data from a plurality of data output circuits 19₀, 19₁, 19₂, ... 19_(p), respectively through different first-side transmission lines 39₀, 39₁, 39₂, ... 39_(m), and which can supply data to a plurality of data input circuits 17₀, 17₁, 17₂, ... 17_(p), respectively through different first-side transmission lines 49₀, 49₁, 49₂, ... 49_(m), where the number of the first-side transmission lines 39₀, 39₁, 39₂, ... 39_(m), or 49₀, 49₁, 49₂, ... 49_(m) which are connected to one second-side transmission line 59 or 69, correspond to a concentration rate. e.g., the number of the first-side transmission lines 39₀, 39₁, 39₂, ... 39_(m), or 49₀, 49₁, 49₂, ... 49_(m) which are connected to one second-side transmission line 59 or 69, is equal to a concentration rate when data transmission rates in both the first and second sides are equal.

The above basic constructions of FIGS. 1 and 2 are utilized to construct a line concentrator wherein a concentration rate is easily changed, and ineffective use of space for installing a plurality of concentrators for a group of subscriber channels is unnecessary, as explained below in the embodiment of the present invention.

FIGS. 3 and 4 show an outline of the construction of a small size exchange system, such as a private branch exchange system.

In FIG. 3, reference numeral 7 denotes a multiplexer, 8 denotes a speech path memory, 9 denotes a demultiplexer, 10 denotes a supervisory memory, 11 denotes a speech path control memory, 12 denotes a bus, and 13 denotes a call processor.

In FIG. 4, reference numerals 3₀, 3₁, 3₂, ... 3₇, 4₀, 4₁, 4₂, ... 4₇ ;,each denote a data highway in the subscriber side, 5₀, 5₁, 5₂, ... 5₇, 6₀, 6₁, 6₂, ... 6₇, each denote a data highway in the subscriber side, 1₀, 1₁, 1₂, ... 1₁₅ each denote a subscribers package, 2 denotes an interface circuit and 26 denotes a connection unit.

FIG. 5 shows the construction of each subscribers package in FIG. 4.

In FIG. 5, reference numeral 21 denotes a multiplexer, 22 denotes a demultiplexer, 23 denotes a line processor, 20₀, 20₁, 20₂, ... 20₁₄ each denote a line circuit, 24₀, 24₁, 24₂, ... 24₁₄ each denotes a subscriber line, and 25₀, 25₁, 25₂, ... 25₁₄ each denote a subscriber's terminal (telephone).

Each of the line circuits 20₀, 20₁, 20₂, ... 20₁₄ is connected with a corresponding one of the subscribers' terminals 25₀, 25₁, 25₂, ... 25₁₄ through the corresponding subscriber lines 24₀, 24₁, 24₂, ... 24₁₄, respectively. Each line circuit carries out operations of transformation between a two-line system (on the side of the subscribers, terminals) and a four-line system (on the side of the exchange system), analog/digital transformation, loop supervision, including detection of calling, receiving of a dialing pulse, a ringing, a battery feeding to the corresponding subscriber, and the like.

The data received from the subscribers in all the line circuits 20₀, 20₁, 20₂, ... 20₁₄, and transformed as above are multiplexed with control data from the line processor 23, in the multiplexer 21 in each subscribers package. The output terminal of the multiplexer 21 is connected to one of the data highways 3₀, 3₁, 3₂, ... 3₇ in the subscriber side, and the multiplexed data is output on the data highway 3_(j).

The data on the data highways 3₀, 3₁, 3₂, ... 3₇ are transmitted through the interface circuit 2 and the data highways 5₀, 5₁, 5₂, ... 5₇ to the multiplexer 7 (shown in FIG. 3).

The multiplexer 7 further multiplexes the data on the data highways 5₀, 5₁, 5₂, ... 5₇ together with control data from the supervisory memory 10, and the time slots in the multiplexed data are exchanged through reading and writing operations in the speech path memory 8.

The reading address or writing address of data of each time slot in the speech path memory 8 is given from the speech path control memory 11, where the content of the speech path control memory 11 is written by the call processor 13.

The call processor 13 collects the information on requests and statuses regarding communication through the exchange system of all the subscribers, which is necessary to carry out exchange operations, from all the subscribers packages 1₀, 1₁, 1₂, ... 1₁₅.

This information is collected by the line processor 23 from all the line circuits 20₀, 20₁, 20₂, ... 20₁₄ in each subscribers package 1₀, 1₁, 1₂, ... 1₁₅, and is then transferred from the line processor 23 in each subscribers package 1₀, 1₁, 1₂, ... 1₁₅, to the supervisory memory 10, by using a channel provided between the supervisory memory 10 and the line processors for transferring control data therebetween. The call processor 13 reads the information transferred from all the line processors 23, in the supervisory memory 10. Thus, based on the dialing information obtained as above, the call processor 13 writes speech path control address for exchanging time slots of the input of the speech path memory 8, on the speech path control memory 11.

The output of the speech path memory 8 is demultiplexed in the demultiplexer 8. The demultiplexed data except the control data which is transferred from the line processors 23, are transmitted through the data highways 6₀, 6₁, 6₂, ... 6₇, the interface circuit 2, and the data highways 4₀, 4₁, 4₂, ... 4₇, to each subscribers package 1₀, 1₁, 1₂, ... 1₁₅, while the control data which is transferred from the line processors 23 is written in the supervisory memory 10.

The demultiplexer 22 in each subscribers package 1_(j) receives the data transmitted on the data highways 4₀, 4₁, 4₂, ... 4₇, and the demultiplexes it, and delivers the demultiplexed data except the control data from the supervisory memory 10, to each line circuit 20₀, 20₁, 20₂, ... 20₁₄, while the control data transmitted from the supervisory memory 10 is delivered to the line processor 23.

The call processor 13 writes control data which should be transmitted to the line processors 23, in the supervisory memory 10. The control data written in the supervisory memory 10 are then output to the multiplexer 7 to be multiplexed with the data from the data highways 5₀, 5₁, 5₂, ... 5₇, the time slots of the control data are respectively exchanged to the time slots which are to be received by the objective subscribers packages, in the speech path memory 8. The data wherein their time slots have been exchanged, are demultiplexed in the demultiplexer 9, and are then delivered to respective data highways 6₀, 6₁, 6₂, ... 6₇ to which the respective objective subscribers packages 1₀, 1₁, 1₂, ... 1₁₅ are connected through the interface circuit 2 and the data highways 4₀, 4₁, 4₂, ... 4₇.

The demultiplexer 22 in each subscribers package 1₀, 1₁, 1₂, ... 1₁₅ receives the time slots assigned to its own subscribers package from a corresponding data highways 4_(j), and thus, the control data transmitted from the supervisory memory 10 is delivered to the objective line processor 23 as mentioned above.

The line processor 23 controls all the line circuits 20₀, 20₁, 20₂, ... 20₁₄, the multiplexer 21, and the demultiplexer 22, based on the control data received from the supervisory memory 10 as above.

FIG. 6 shows the assignment of the time slots on each data highway 3₀, 3₁, 3₂, ... 3₇, 4₀, 4₁, 4₂, ... 4₇, 5₀, 5₁, 5₂, ... 5₇, and 6₀, 6₁, 6₂, ... 6₇ in the construction of FIG. 4 in the embodiment of the present invention.

As shown in FIG. 6, each data highway transmits 32 time slots TS₀, TS₁, TS₂, ... TS₃₁, with a period of 125 μs.

FIG. 7 shows the connections of the plurality of subscribers packages 1₀, 1₁, 1₂, ... 1₁₅ with the data highways 3₀, 3₁, 3₂, ... 3₇, or data highways 4₀, 4₁, 4₂, ... 4₇ in a non-concentrated connection mode in the embodiment of the present invention having the construction of FIG. 4, wherein "P0", "P1", ... "P15", each denote an identification number of the subscribers packages, and each corresponds to one of the subscribers packages 1₀, 1₁, 1₂, ... 1₁₅, and "A" and "B" each denote a connecting position of each data highway with a subscribers package.

Each of the data highways 3₀, 3₁, 3₂, ... 3₇ is connected with the output terminals of the multiplexers 21 in two of the subscribers packages 1₀, 1₁, 1₂, ... 1₁₅. As explained before with reference to FIG. 5, each subscribers package contains fifteen line circuits 20₀, 20₁, 20₂, ... 20₁₄, and one time slot is assigned for sending data from each line circuit 20₁, 20₁, 20₂, ... 20₁₄ toward the speech path memory 8, and one time slot is assigned for sending control data from the line processor 23 toward the speech path memory 8.

Similarly, each of the data highways 4₀, 4₁, 4₂, ... 4₇ is connected with the input terminals of the demultiplexers 22 in two of the subscribers packages 1₀, 1₁, 1₂, ... 1₁₅. One time slot is assigned for receiving data from the speech path memory 8 to each line circuit 20₀, 20₁, 20₂, ... 20₁₄, and one time slot is assigned for sending control data from the speech path memory 8 to the line processor 23.

As explained above, in the non-concentrated state, the number of time slots in the subscriber side and the number of time slots in the speech path memory side are the same. In the conventional small size exchange system, such as a private branch exchange system, no line concentration system is provided.

The above non-concentrated system is suitable for the situation wherein the traffic of the subscribers is large. However, when the traffic of the subscribers is small, the above non-concentrated exchange system is not effective, i.e., the speech path memory side of the exchange system is not effectively used when the traffic of the subscribers is small in the non-concentrated system.

Therefore, to effectively utilize exchange system, a line concentration system is required to be introduced between the subscriber side and the speech path memory side.

FIG. 8 shows the connections of the plurality of subscribers packages 1₀, 1₁, 1₂, ... 1₁₅ with the data highways 3₀, 3₁, 3₂, ... 3₇, or data highways 4₀, 4₁, 4₂, ... 4₇ in the concentrated connection mode with a concentration rate of two in the embodiment of the present invention having the construction of FIG. 4, wherein "P0", "P1", ... "P15", each denote an identification number of the subscribers packages, and each corresponds to one of the subscribers packages 1₀, 1₁, 1₂, ... 1₁₅, as FIG. 7.

Each of the data highways 3₀, 3₁, 3₂, ... 3₇ is connected with the output terminals of the multiplexers 21 in four of the subscribers packages 1₀, 1₁, 1₂, ... 1₁₅ and each of the data highways 4₀, 4₁, 4₂, ... 4₇ is connected with the input terminals of the demultiplexers 22 in four of the subscribers packages 1₀, 1₁, 1₂, ... 1₁₅.

Since the concentration rates in conventional line concentrators cannot be easily changed as explained before, a plurality of connection units respectively realizing the connections between the subscribers packages and the data highways with respective concentration rates, must be provided, and when changing the concentration rate, disconnecting operation from one connection unit, and connecting operation to the other connection unit must be carried out in the conventional exchange system.

In practice, the above connections of the plurality of subscribers packages 1₀, 1₁, 1₂, ... 1₁₅ with the data highways 3₀, 3₁, 3₂, ... 3₇, or data highways 4₀, 4₁, 4₂, ... 4₇ are realized in the connection unit 26 in a private branch exchange system. The connection unit 26 provides a plurality of slots which enable the above connection.

FIG. 9 shows the arrangement of the connections of the plurality of subscribers packages 1₀, 1₁, 1₂, ... 1₁₅ with the data highways 3₀, 3₁, 3₂, ... 3₇, 4₀, 4₁, 4₂, ... 4₇ in the connection unit 26 in the construction of FIG. 4, wherein "P0", "P1", ... "P15" each denote an identification number of the subscribers packages, and each corresponds to one of the subscribers packages 1₀, 1₁, 1₂, ... 1₁₅, as FIG. 7, and "HW0", "HW1", ... "HW7" respectively correspond to the data highways 3₀, 3₁, 3₂, ... 3₇, and "HW0'", "HW1'", ... "HW7'" respectively correspond to the data highways 4₀, 4₁, 4₂, ... 4₇.

The embodiment of the present invention provides a construction wherein a switching of the concentration rate between a non-concentrated mode and the concentrated mode, maintaining the connection (without the disconnection and the reconnection as in the conventional system) between the plurality of subscribers packages 1₀, 1₁, 1₂, ... 1₁₅ and the data highways 3₀, 3₁, 3₂, ... 3₇, 4₀, 4₁, 4₂, ... 4₇ in the connection unit 26 in the construction of FIG. 4, as shown in FIG. 9.

The above construction according to the present invention is provided in the interface circuit 2 in the following embodiments.

FIGS. 10 and 11 show the construction of the first embodiment of the present invention for allowing the change of the concentration rate, where FIG. 10 shows the construction provided between the data highways 3₀, 3₁, 3₂, ... 3₇ in the subscriber side and the data highways 5₀, 5₁, 5₂, ... 5₇ in the speech path memory side and FIG. 11 shows the construction provided between the data highways 6₀, 6₁, 6₂, ... 6₇ in the speech path memory side and the data highways 4₀, 4₁, 4₂, ... 4₇ in the subscriber side, in the interface circuit 2 in the arrangement of FIG. 4.

In FIG. 10, reference numeral 30₀, 30₁, 30₂, and 30₃ each denote a switching circuit, 31₀, 31₁, 31₂, 31₃, 32₀, 32₁, 32₂, and 32₃ each denote a switch, d1, d2, and d3 each denote a driver circuit, "a", "b", and "c" each denote a contact of each switch, and "A" and "B" each denote a connecting position of each data highway with a subscribers package.

The "b" contact of each of the switches 31₀, 31₁, 31₂, 31₃, 32₀, 32₁, 32₂, and 32₃ can be connected with either of the corresponding "a" contact or "c" contact. When the "b" contact of each of the switches 31₀, 31₁, 31₂, 31₃, 32₀, 32₁, 32₂, and 32₃ is connected with the corresponding "a" contact, a connection equivalent to the connection shown in FIG. 7 is realized in the construction of FIG. 10, or when the "b" contact of each of the switches 31₀, 31₁, 31₂, 31₃, 32₀, 32₁, 32₂, and 32₃ is connected with the corresponding "c" contact, a connection equivalent to the connection shown in FIG. 8 is realized in the construction of FIG. 10.

Similarly, in FIG. 11, reference numeral 33₀, 33₁, 33₂, and 33₃ each denote a switching circuit, 34₀, 34₁, 34₂, 34₃, 35₀, 35₁, 35₂, and 35₃ each denote a switch, d1, d2, and d3 each denote a driver circuit, "a'", "b'", and "c'" each denote a contact of each switch, and "A'" and "B'" each denote a connecting position of each data highway with a subscribers package.

The "b'" contact of each of the switches 34₀, 34₁, 34₂, 34₃, 35₀, 35₁, 35₂, and 35₃ can be connected with either of the corresponding "a'" contact or "c'" contact. When the "b'" contact of each of the switches 34₀, 34₁, 34₂, 34₃, 35₀, 35₁, 35₂, and 35₃ is connected with the corresponding "a'" contact, a connection equivalent to the connection shown in FIG. 7 is realized in the construction of FIG. 11, or when the "b'" contact of each of the switches 34₀, 34₁, 34₂, 34₃, 35₀, 35₁, 35₂, and 35₃ is connected with the corresponding "c'" contact, a connection equivalent to the connection shown in FIG. 8 is realized in the construction of FIG. 11.

FIGS. 12 and 13 show the construction of the second embodiment of the present invention for allowing the change of the concentration rate, where FIG. 12 shows the construction provided between the data highways 3₀, 3₁, 3₂, ... 3₇ in the subscriber side and the data highways 5₀, 5₁, 5₂, ... 5₇ in the speech path memory side, and FIG. 13 shows the construction provided between the data highways 6₀, 6₁, 6₂, ... 6₇ in the speech path memory side and the data highways 4₀, 4₁, 4₂, ... 4₇ in the subscriber side in the interface circuit 2 in the arrangement of FIG. 4.

In FIG. 12, reference numeral 40₀, 40₁, 40₂, and 40₃ each denote an OR gate, 41₀, 41₁, 41₂, and 41₃ each denote a selector, 42₀, 42₁, 42₂, ... 42₇, each denote a driver circuit, and "A" and "B" each denote a connecting position of each data highway with a subscribers package.

One terminal of each of the data highways 3₀ and 3₁ are connected to the input terminals of the OR gate 40₀, one terminal of each of the data highways 3₂ and 3₃ are connected to the input terminals of the OR gate 40₁, one terminal of each of the data highways 3₄ and 3₅ are connected to the input terminals of the OR gate 40₂, and one terminal of each of the data highways 3₆ and 3₇ are connected to the input terminals of the OR gate 40₃. The above terminal of the data highway 3₀ and the output of the OR gate 40₀ are applied to the selector 41₀, the above terminal of the data highway 3₁ and the output of the OR gate 40₁ are applied to the selector 41₁, the above terminal of the data highway 3₂ and the output of the OR gate 40₂ are applied to the selector 41₂, and the above terminal of the data highway 3₃ and the output of the OR gate 40₃ are applied to the selector 41₃. The output terminals of the selectors 41₀, 41₁, 41₂, and 41₃ are each connected to the data highways 5₀, 5₁, 5₂, and 5₃, through the driver circuits 42₀, 42₁, 42₂, and 42₃, respectively. The above terminals of the data highways 3₄, 3₅, 3₆, and 3₇ are each connected through the driver circuits 42₄, 42₅, 42₆, and 42₇ to the data highways 5₄, 5₅, 5₆, and 5₇, respectively.

A control signal C is applied to the control input of all the selectors 41₀, 41₁, 41₂, and 41₃. When the control signal C is "1", the selectors 41₀, 41₁, 41₂, and 41₃ each select the inputs from the data highways 3₀, 3₁, 3₂, and 3₃, respectively, and thus, a connection equivalent to the connection shown in FIG. 7 is realized in the construction of FIG. 12. Or when the control signal C is "0", the selectors 41₀, 41₁, 41₂, and 41₃ each select the inputs from the OR gates 40₀, 40₁, 40₂, and 40₃, respectively, and thus, a connection equivalent to the connection shown in FIG. 8 is realized in the construction of FIG. 13.

In FIG. 13, reference numeral 43₀, 43₁, 43₂, ... 43₇, 47₀, 47₁, 47₂, 47₃, 48₀, 48₁, 48₂, and 48₃ each denote a tristate buffer circuit, and "A'" and "B'" each denote a connecting position of each data highway with a subscribers package..

One terminal of each of the data highways 6₀, 6₁, 6₂, ... 6₇, is connected with a corresponding one of the data highways 4₀, 4₁, 4₂, ... 4₇, through the corresponding one of the tristate buffer circuits 43₀, 43₁, 43₂, ... 43₇, respectively. The above terminal of the data highway 6₀ is further connected with the input terminals of both the tristate buffer circuits 47₀ and 48₀, the above terminal of the data highway 6₁ is further connected with the input terminals of both the tristate buffer circuits 47₁ and 48₁, the above terminal of the data highway 6₂ is further connected with the input terminals of both the tristate buffer circuits 47₂ and 48₂, and the above terminal of the data highway 6₃ is further connected with the input terminals of both the tristate buffer circuits 47₃ and 48₃. The output terminals of the tristate buffer circuits 47₀, 47₁, 47₂, 47₃ are each connected to the data highways 4₀, 4₂, 4₄, and 4₆, respectively. The output terminals of the tristate buffer circuits 48₀, 48₁, 48₂, 48₃ are each connected to the data highways 4₁, 4₃, 4₅, and 4₇, respectively.

The above-mentioned control signal C is applied to the control terminals of the tristate buffer circuits 43₀, 43₁, 43₂, ... 43₇, and the inverted signal C of the control signal C is applied to the control terminals of the tristate buffer circuits 47₀, 47₁, 47₂, 47₃, 48₀, 48₁, 48₂, and 48₃.

When the control signal C is "1", the data highways 6₀, 6₁, 6₂, ... 6₇, is connected with a corresponding one of the data highways 4₀,4₁, 4₂, .. 4₇, respectively, and thus, a connection equivalent to the connection shown in FIG. 7 is realized in the construction of FIG. 12. Or when the control signal C is "0", the data highway 6₀ is connected with both the data highways 4₀ and 4₁, the data highway 6₁ is connected with both the data highways 4₂ and 4₃, the data highway 6₂ is connected with both the data highways 4₄ and 4₅, and the data highway 6₃ is connected with both the data highways 4₆ and 4₇. Thus, a connection equivalent to the connection shown in FIG. 8 is realized in the construction of FIG. 13.

The above control signal C can be generated, for example, by providing a manual switch (not shown) which is connected with the interface circuit, or by control from the call processor 13.

In the construction explained above, the timings of sending and receiving of data from and at each subscribers package 1₀, 1₁, 1₂, ... 1₁₅, are controlled by the call processor 13 through the line processor 23 in each subscribers package so that data from two subscribers packages are not doubly input onto the same time slot on a data highway, and data from one time slot on a data highway is not doubly received at two subscribers packages.

Although the constructions realizing a switching of connections between the non-concentrated mode and the concentrated mode with the concentration rate of two, it is easily understood that a connection switching circuit, which is provided between a plurality of subscriber side transmission lines and a plurality of speech path memory side transmission lines, for connecting a controlled number (one or two in the above embodiment) of corresponding subscriber side transmission lines with a corresponding one of the plurality of speech path memory side transmission lines, can be constructed by providing: a plurality of modes of connection paths, where each mode of the connection paths realize the connections between a predetermined number of the subscriber side transmission lines and a corresponding one of the plurality of speech path memory side transmission lines, and the predetermined number is predetermined for each mode; and a plurality of gates which are located in all the connection paths, and are each controlled to pass or not to pass an applied signal so that only one mode of the connection paths, where the predetermined number in the mode is equal to the above controlled number, is realized at one time. This is shown in FIG. 13, and it is known that the selectors in the construction of FIG. 12 can be constructed by the gate circuits as above-mentioned.

Therefore, a line concentration system wherein a switching between any concentration rates among a plurality of predetermined concentration rates can be easily carried out by a control signal for controlling gates as above, can be realized according to the present invention. 

I claim:
 1. A line concentration system comprising:a plurality of first-side transmission lines capable of transmitting data; a plurality of data input means for inputting data at a controlled timing from a first-side transmission line to which each data input means is connected; a plurality of second-side transmission lines capable of transmitting a predetermined number of channels of data; connection switching means, provided between said plurality of first-side transmission lines and said plurality of second-side transmission lines, for connecting each of a number m of said plurality of first-side transmission lines with one of said plurality of second-side transmission lines, where m corresponds to a concentration rate and the concentration rate can be varied in accordance with a control input; and a data input timing control means for providing the controlled timing for said plurality of data input means so that the data inputting is not simultaneously performed by two of said data input means.
 2. A line concentration system according to claim 1,wherein each of said data input means comprisesa plurality of line circuits, each provided for a corresponding subscriber, to carry out operations including loop supervision, receiving a dialing signal, or ringing, to obtain data from a corresponding subscriber, a demultiplexer connected to demultiplex data from said first-side transmission line connected to a corresponding data input means and output demultiplexed data corresponding line circuits under control of said line and a line processor connected to control the timing of the data input from the first-side transmission line to said demultiplexer based on control information given from said call processor and to control reception of the demultiplexed data output from said demultiplexer to said line processor, and wherein said data input timing control means comprises a call processor, operatively connected to said input means and said line processor, to collect all statuses of all said input means regarding use of the corresponding first-side transmission lines from a corresponding line processor and to give the control information on timing of the data input, from the corresponding first-side transmission line to a corresponding demultiplexer, to all said processors in all said plurality of data input means.
 3. A line concentration system according to claim 1, wherein said connection switching means comprises:a plurality of modes of connection paths, where each mode of the connection paths realize the connections between a predetermined number of said first-side transmission lines and a corresponding one of said plurality of second-side transmission lines, the predetermined number being predetermined for each mode; and a plurality of gates located in all the connection paths and each controlled to selectively pass an applied signal so that only one mode of the connection paths, where the predetermined number in the mode is equal to the controlled number, is realized at one time.
 4. A line concentration system comprising:a plurality of first-side transmission lines capable of transmitting data; a plurality of data output means for outputting data at a controlled timing from a first-side transmission line to which each data output means is connected; a plurality of second-side transmission lines capable of transmitting a predetermined number of channels of data; connection switching means, provided between said plurality of first-side transmission lines and said plurality of second-side transmission lines, for connecting each of a number m of said plurality of first-side transmission lines with one of said plurality of second-side transmission lines, where m corresponds to a concentration rate and the concentration rate can be varied in accordance with a control input; and a data output timing control means for providing the controlled timing for said plurality of data output means so that the data outputting is not simultaneously performed by two of said data output means.
 5. A line concentration system according to claim 4,wherein each of said data output means comprisesa plurality of line circuits, each provided for a corresponding subscriber, each of said line circuit means for carrying out operations including loop supervision, receiving a dialing signal, or ringing, to obtain data from a corresponding subscriber, a multiplexer connected to multiplex data from said plurality of line circuits and output multiplexed data onto said first-side transmission line which is connected to a corresponding data output means, and a line processor connected to control the timing of the data output from the first-side transmission line to said demultiplexer based on control information given from said call processor, and wherein said data input timing control means comprises a call processor, operatively connected to said output means and said line processor, to collect all statuses of all said output means regarding use of the corresponding first-side transmission line from a corresponding line processor and to give the control information on timing of the date outputted, from said multiplexer, to all said line processors in all said plurality of data output means.
 6. A line concentration system according to claim 4, wherein said connection switching means comprises:a plurality of modes of connection paths, where each mode of the connection paths realize the connections between a predetermined number of said first-side transmission lines and a corresponding one of said plurality of second-side transmission lines, the predetermined number being predetermined for each mode; and a plurality of gates located in all the connection paths and each controlled to selectively pass an applied signal so that only one mode of the connection paths, where the predetermined number in the mode is equal to the controlled number, is realized at one time. 